1. Field of the Invention
The present invention relates to a display panel using organic electroluminescence devices (hereafter referred to as organic EL devices) and a method of manufacturing the display panel, and more particularly to an organic EL color display panel having light emitting portions in a plurality of luminous colors and to a method of manufacturing the organic EL color display panel.
2. Description of the Related Art
There have been disclosed conventional organic EL display panels, for example, in JP-A8-315981, 10-312886 and 11-194585.
In such organic EL display panels, during the process of making an organic EL display panel, it is generally difficult to pattern organic EL medium layers or electrode layers after forming the organic EL medium layers because of low heat resistance, low solvent resistance and low humidity resistance of the organic EL medium used in charge injection layers and light emitting layers. For example, when the photolithography generally used to pattern thin films is used for the patterning in the organic EL display panel, a problem arises that the organic EL device characteristics are degraded by infiltration of solvent into photoresist, by a high-temperature ambient gas during baking of photoresist, by infiltration of photoresist development liquid into the devices, or by damages to devices by plasma during dry etching.
Other examples of the patterning method include a vapor deposition method that uses a mask to pattern the organic EL medium layers and electrode layers. However, because of the wraparound of vapor that may occur in gaps between the mask and the substrate and the shadowing caused by projections and debris, the coverage of the organic EL medium may become insufficient. This in turn causes characteristic degradations during the operation of the organic EL display panel, such as current leakage and poor emission of light, which stand in the way of performance enhancement of the organic EL display panel.
Also, in the conventional full color organic EL display panel, when the same organic EL material is used commonly for the organic EL medium layers of different luminous colors, the layers are formed under the same conditions irrespective of the colors. Hence, the light emitting characteristics of the individual light emitting portions cannot be optimized according to the colors, which is detrimental to enhancing the performance of the full color organic EL display panel.
The present invention has been accomplished under these circumstances to provide a high performance organic EL display panel and a method of manufacturing such a display panel.
In order to achieve the above object, according to one aspect of the invention, there is provided a method of manufacturing an organic electroluminescent display panel having light emitting portions in a plurality of luminous colors formed on a substrate, the method comprising: a step of forming first electrodes on the substrate; an organic layer forming step of forming organic layers by deposition; a light emitting layer forming step of forming different light emitting layers for different luminous colors in desired areas; and a step of forming second electrodes; wherein in the organic layer forming step, the organic layers are formed by an angle deposition method.
According to the present invention, there is provided a method of manufacturing an organic electroluminescent display panel having light emitting portions in a plurality of luminous colors formed on a substrate, the method comprising: a step of forming first electrodes on the substrate; a first organic layer forming step of simultaneously forming same first organic layers common to all the luminous colors in light emitting areas by deposition; a second organic layer forming step of forming different second organic layers for different luminous colors in desired areas by deposition; a light emitting layer forming step of forming different light emitting layers for different luminous colors in desired areas; and a step of forming second electrodes; wherein the first organic layers are formed by an angle deposition method and the second organic layers are deposited at a deposition angle smaller than that of the angle deposition method.
According to the present invention, there is provided an organic electroluminescent display panel having light emitting portions in a plurality of luminous colors formed on a substrate; the display panel comprising: first electrodes formed on the substrate; organic layers formed by deposition; light emitting layers formed in desired areas according to the luminous colors; and second electrodes; wherein the organic layers are formed by an angle deposition method.
According to the present invention, there is provided an organic electroluminescent display panel having light emitting portions in a plurality of luminous colors formed on a substrate; the display panel comprising: first electrodes formed on the substrate; first organic layers formed in light emitting areas at one time by deposition; second organic layers formed in desired areas and being different among different luminous colors; and second electrodes; wherein the first organic layers are formed by an angle deposition method and the second organic layers are deposited at a deposition angle smaller than that of the angle deposition method.
According to another aspect of the present invention, there is provided a method of manufacturing an organic electroluminescent display panel having light emitting portions in a plurality of luminous colors formed on a substrate, the method comprising: a step of forming first electrodes on the substrate; an organic layer forming step of forming organic layers in associated light emitting areas, the organic layers having different thicknesses for different luminous colors; a light emitting layer forming step of forming light emitting layers for different luminous colors in the associated light emitting areas; and a step of forming second electrodes.
According to the present invention, there is provided a method of manufacturing an organic electroluminescent display panel having light emitting portions in a plurality of luminous colors formed on a substrate, the method comprising: a step of forming first electrodes on the substrate; a first organic layer forming step of forming organic layers in associated light emitting areas on the substrate on which the first electrodes were formed, the organic layers having different thicknesses for different luminous colors; a light emitting layer forming step of forming light emitting layers for different luminous colors in the associated light emitting areas after performing the first organic layer forming step; and a step of forming second electrodes after performing the light emitting layer forming step.
According to the present invention, there is provided an organic electroluminescent display panel having light emitting portions in a plurality of luminous colors formed on a substrate; the display panel comprising: first electrodes formed on the substrate; first organic layers having different thicknesses for different luminous colors in associated light emitting areas on the substrate on which the first electrodes were formed; light emitting layers formed on the first organic layers on the light emitting areas corresponding to the different luminous colors; and second electrodes formed on the light emitting layers.